Process of recovering sodium carbonate sulphate from saline waters



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To all whom; it may concern:

Be it known that l, GEoRoEB'. BURNHAM, a'citizen of the United States, and a resident of Boros'olvay, San Bernardino. County,

State of Californimhave invented a new and useful Process of Recovering 'Sodium Carbonate Sulphate from Saline Waters, I of which. the following is a specification.

'lhe inventlon relates to a process of recovering sodium carbonate sulphate from saline waters containing the'same and par ticularly from the brines of the alkali lakes of the Western United States.

'An object of the invention isto provide a process of recovering sodium carbonate sulphate from liquors containing sodium, 1

carbonate and sulphate ions.

Theinvention will be set forth at length inthe following description, Where I shall outline full, one form of the process of my invention. l shall describe the processes applied to the brine. of Searles Lake in California, but it is to be understood that the process is not limited to this particular solutions formedby dissolving sodium carbrine. *Th-e process may be also applied to bonate and sodium sulphate in Water.

7 Searles Lake brine contains sodium and potassium, chloride, sulphate, carbonate and borate. By the process of my invention, I am able to employ natural temperatures for evaporation and cooling, .and I prefer to make use'of the temperature variations of lake brine, which is 'at a temperature of from Winter and summer and day and night, but artificial variations in temperature and artificial evaporation may be'employed when desired.

In the preferred form of my process, the

22 "C'to 25 C. the year round, is pumped,

late in the fall of the year, into moderately shallow solar evaporation ponds, which ll shall term the No. 1 ponds and inthese ponds some of the sulphates are crystillized out by cooling of the brine due to the temperatures prevailing at that time. The brine remains in these shallow ponds during November and part of December, and the evaporation of the water during this time brings the concentration of the potash as high as is possible,

consistentwith the subsequent cooling that-v the brine will receive during the coldest part of winter. 7

During the cold nights of December and January, the brine is flowed from the No. 1

ponds into very shallow nightly cooling Specificationof-LettersPatent. fip m m qwa gg W i Application filed June 30, 1919; Serial No. 307,752.

ponds (No.2 ponds) which are about one.

inch deep, so that the brine will become thoroughly chilled. This extreme cooling causes nightly temperatures of winter.

lin -the coldest hours of the morning, the chilled brine is pumped from the shallow No. 2 ponds, into a deep pond (ppnd.#3)

in which the brine, on account of its depth,

is not appreciably raised in temperature.

during the day. The agitation of the brine. caused by pumping helpsto crystallize out the sodium sulphates, carbonates and borates with which the brine is inclined to be supersaturated at the" cold temperatures of .the'rmorning; The sodium sulphate and carbonate saltstend to crystallize out more rapidly'than the borax and settle to the bottom of the deep pond #3-in "a few hours. The brine is then pumped fromdeep pond #3 to another deep pond #4, to separate the deposited crsytals from the brine.

The crystals of sodium sulphate and sod'ium carbonate deposited in pond #3, are then redissolved in water. The solution thus formed is evaporated, preferably in solar 'ponds, whereupon crystals of so-.

dium carbonate sulphate These crystals are then separated from the remaining liquor. The salt thus formed has the general formula of NaACU fiOQ or Na.,(CU ,SO )nH O.

A modified form of the rocess of obtaining sodium carbonate sulp 'ate from Searles Lake brine consists in evaporating the brine during the summer. As evaporation occurs sodium chloride first crystallizes out and then, upon further evaporation, sodium chloride and sodium carbonate sulphate crystallize out together. The brine is then removed fromthe deposited crystals and the crystals of thetwo compounds separated by mechanical means. The sodium chloride crystals are much larger than the sodium carbonate sulphate crystals, so that they may be readily separated by screening, or otherwise.

I claim: 1. The process of producing sodium carbonate sulphate, which consists in mixing soare' formed. 7

' which consists in partially concentratingdium carbonate and sodium fsulphatedin water to form a solution, lution by summer solar heat whereby crystals of sodium carbonate sulphate are deposited, and separatingthe remaining liqnor from the deposited crystals.

2. The process of recovering sodium carbonate' sulphate from Searles Lake. brine,

and cooling the brine to crystallize, out sodium carbonate and sodium sulphate, separating the remaining liquor from thecrystals, redissolving the crystals andevaporating the solution thus formed by summer sobonate sulphate from which consists in and cooling the brine to crystallize out sodilar heat to crystallize out sodium carbonate sulphate.

3. The process of recovering sodium car- Searles Lake brine,-

partially concentrating um sulphate and sodium carbonate, rem'oving the remaining liquorfrom thedeposited crystals, redissolving the crystals in water,

evaporating the sowarm temperatures to crystallize out sodium carbonate sulphate and recovering the deposited crystals.

5. The process of producing sodium carbonatesulphate from Searles Lake brine, which consists "in slowly evaporating the brine to produce saturation with sodium carbonate sulphate and continuing theslow evaporation to crystallize out sodium carbonate sulphate."

In testimony whereof, I haveihereunto set my hand at 'San Francisco, California. this 9th day of June, 1919.

GEORGE B. BURN HAM.

. In presence of- H, G., Pnos'r. 

